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08-31-2016, 02:12 AM   #91
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QuoteOriginally posted by D1N0 Quote
Well maybe people should use the long exposure nr when they are taking long exposures.
I don't think it's the only problem, i see white dots on 1/1000s Iso 6400-12800 ....
(i'll post the link this afternoon)

08-31-2016, 02:36 AM   #92
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Then you should return it. This is a long exposure problem.
08-31-2016, 02:58 AM   #93
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QuoteOriginally posted by D1N0 Quote
Well maybe people should use the long exposure nr when they are taking long exposures.
That might be ok if you are doing one or two long exposures, but spending half the night doing dark frames is not acceptable if you are doing lots of LE, for instance astro photography with 20 or more LE. And a LE doesn’t have to be that long before the dots appear, in some cases.

Also DFS (dark frame subtraction/ long exposure NR) with high iso does add noise to the result. Since a noisy image minus a noisy dark frame doesn’t really result in less noise.
08-31-2016, 03:43 AM   #94
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QuoteOriginally posted by Tjompen1968 Quote
Keep us posted on what the Swedes say...
Right, I got an answer from Kameraservice Kungsör here in Sweden. They don't know what i'm talking about, but told me to send it in.

Hej
Det låter konstigt att du hört att vissa fått skicka på service för det, vi har inte fått in en enda K-1 med detta problem till oss från någon av de nordliga länderna.
Du får skicka hit din kamera så får vi kika på den åt dej.
Skicka med en felbeskrivning, returadress, kvitto, e-postadress & gärna ett mobilnr för SMS-avisering vid returen.


and translated into English:

"Hi.
It sounds odd that you've heard that some people has had to send in their camera for this, we haven't received a single K-1 with this problem from any of the Nordic countries.
You'll have to send your camera here so that we can have a look at it for you.
Attach description of the error, return address, receipt, email address and preferrably a mobile telephon number for SMS notification upon return."


Not sure what to make of it, since it seems futile to send in a camera they don't know how to fix...

08-31-2016, 04:55 AM - 1 Like   #95
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They are very good at what they do at Kamera Service so I think they will figure it out.
I will send them an e-mail later with the same problem so that they understand that you are not alone.
08-31-2016, 04:55 AM   #96
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QuoteOriginally posted by Gimbal Quote
That might be ok if you are doing one or two long exposures, but spending half the night doing dark frames is not acceptable if you are doing lots of LE, for instance astro photography with 20 or more LE. And a LE doesn’t have to be that long before the dots appear, in some cases.

Also DFS (dark frame subtraction/ long exposure NR) with high iso does add noise to the result. Since a noisy image minus a noisy dark frame doesn’t really result in less noise.
Standard in-camera DFS does in fact reduce some kinds of "noise" although you are right that it increases others. To the extent that "hot pixels" have a fixed pattern, DFS will largely eliminate them. It will also eliminate amp glow which has been a problem on some digital cameras but not the K-1 to my knowledge. The low-level background read noise will be increased somewhat but that's a small price to pay for getting rid of very bright hot pixels.

If the locations of hot pixels and relative brightnesses does not change much over time (e.g., the hot pixel brightness of pixel 2,478,354 is always 2.3X higher than the hot pixel brightness of pixel 4,574,633) ), it should be possible to remove hot pixels by collecting your own dark frames as a separate process (e.g., before or after an astrophotography session) and statistically estimating the magnitude level of the hot pixel effect in each image frame. Moreover, to the extent that one collects and stacks a set of dark frames for the hot pixel calibration image, the result would be a correction that removes hot pixels WITHOUT increasing the level of read noise. That's the theory, but I don't know of any software that has this functionality built in so it could become a workflow issue. (Note: a bit of poking on the internet suggests StarStax, StarTrails or Image Stacker might do this.)
08-31-2016, 05:02 AM   #97
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I just do not find it acceptable that ISO100 exposure, 30secs, pushed 2 stops gives white dots. Just about all modern cameras including canons make it possible. And that is without LENR. Oh yea, 120 seconds at ISO3200 requiring dark frame I understand and that is okay. Nikon d810A can do that even without LENR.
08-31-2016, 05:26 AM - 1 Like   #98
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QuoteOriginally posted by photoptimist Quote
it should be possible to remove hot pixels by collecting your own dark frames as a separate process (e.g., before or after an astrophotography session) and statistically estimating the magnitude level of the hot pixel effect in each image frame. Moreover, to the extent that one collects and stacks a set of dark frames for the hot pixel calibration image, the result would be a correction that removes hot pixels WITHOUT increasing the level of read noise. That's the theory, but I don't know of any software that has this functionality built in so it could become a workflow issue. (Note: a bit of poking on the internet suggests StarStax, StarTrails or Image Stacker might do this.)
As I understand it Rawtherapee has an automatic dark frame selection function were the program search for a dark frame with the same iso and shutter speed as the light frame, and if several dark frames are found with the same settings they are averaged together.

So as a user I’m supposed to dump all my dark frames in a special dark frame catalog and the program does the rest, or at least that is how I understand the manual. I haven’t tried it myself yet but it is definitely on the to-do list as it sounds neat. Also as a side note Rawtherapee does an excellent job at removing these white dots without using dark frames.

08-31-2016, 05:28 AM - 1 Like   #99
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QuoteOriginally posted by photoptimist Quote
If the locations of hot pixels and relative brightnesses does not change much over time (e.g., the hot pixel brightness of pixel 2,478,354 is always 2.3X higher than the hot pixel brightness of pixel 4,574,633) ), it should be possible to remove hot pixels by collecting your own dark frames as a separate process (e.g., before or after an astrophotography session) and statistically estimating the magnitude level of the hot pixel effect in each image frame. Moreover, to the extent that one collects and stacks a set of dark frames for the hot pixel calibration image, the result would be a correction that removes hot pixels WITHOUT increasing the level of read noise. That's the theory, but I don't know of any software that has this functionality built in so it could become a workflow issue. (Note: a bit of poking on the internet suggests StarStax, StarTrails or Image Stacker might do this.)
"Photography is not a rocket science".

p.s. Sorry I simply could not resist
08-31-2016, 05:30 AM   #100
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All these alternative converters lack in intuitive workflow except perhaps Capture One. So while they might solve something, they might not count as positives in overall user experience.
08-31-2016, 05:55 AM   #101
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QuoteOriginally posted by MJKoski Quote
All these alternative converters lack in intuitive workflow except perhaps Capture One. So while they might solve something, they might not count as positives in overall user experience.
Capture one is a pricey but very good choice for K-1 owners who doesn't need pixel shift and tethering. Version 9.2 supports K-1 without those two functionalities.
08-31-2016, 06:06 AM   #102
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QuoteOriginally posted by MJKoski Quote
All these alternative converters lack in intuitive workflow except perhaps Capture One. So while they might solve something, they might not count as positives in overall user experience.
True, I prefer to use lightroom for a lot of reasons, but in certain situations I have to look elsewhere to get the job done. It’s a hassle but if I find another tool that does a certain job better, then that is the tool I will use for that job (at least if it’s free).
08-31-2016, 07:09 AM   #103
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Here are some PEF files from room temp vs. freezer experiment: 2016-08-25.rar - Google Drive

It is a .RAR archive.
1151.PEF = +23C room temp, ISO3200, 122 seconds
1152.PEF = -18C freezed camera, ISO3200, 122 seconds

Lens cap attached, camera under dark cloth inside a dark box.
08-31-2016, 09:26 AM   #104
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QuoteOriginally posted by MJKoski Quote
I just do not find it acceptable that ISO100 exposure, 30secs, pushed 2 stops gives white dots. Just about all modern cameras including canons make it possible. And that is without LENR.
I thought you posted that Pentax determined that your camera is defective and has offered warranty service. I.e. Your experience may not be typical.


Steve
08-31-2016, 09:55 AM   #105
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I will deliver my camera to service next monday. With some luck I will have a loaner unit by then (from brand new batch!). Let's see what happens.
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